One of the most important issues in MPEG editing is to ensure that
the original video is NOT re-encoded. MPEG compression has its flaws: for every
encoding processing, the image quality slightly degrades. For this reason, the
Automatic should always be used for the "Save as type" selection, if you want
minimal loss of image quality to result in the final MPEG output.

However, if you do select a different template for your output, if you have
added a lot of video fades and transitions, or if you are not sure about your
"Save as type" selection, you can check the Encode Map display.

The above encode map is corresponding to a sample editor project as shown in
the timeline blow. In this example, the re-encoded sections are, starting from
the beginning (left) to the end (right) of the timeline, 1 second fade-in, 2
second transition, 1 second fade-out, 5 second image plus text title, 1 second
fade-in, 2 second transition, and 1 second fade-out.

Since the total length of the project is 75.74 seconds, and the total length
of the re-encoded sections is about 13.00 seconds, the division of the two types
of export are 17.20% re-encoding and 82.80% stream-copy, excluding the slight
difference between video and audio due the rounding error and their different
frame lengths.

You could open the encode map display during your selection
for an export file name, by pressing the Detail button
on the Save As file window.

You could also view the encode map display during or before an export job
by pressing the Detail button on
the Monitor
tab of the Export window.